The major emphasis of this research proposal is an understanding of the mechanism of protein synthesis initiation and elongation. Current efforts are focused upon the purification and characterization of each of the components required for these processes. To date seven of these proteins have been purified and characterized (EF-alpha, EF-2, eIF-2, eIF-2A, eIf-4A, eIF-4C, eIF-4D, eIF-5). EF-beta gamma delta , eIF-31, and eIF-4B are being characterized at present. With these proteins, attempts will be made to identify any additional proteins which have been reported to stimulate either model assays or hemoglobin synthesis. In particular, eIF-1, Co-eIF-2A (as described by Gupta and coworkers), ESP (as described by Ochoa and coworkers), and the 24,000 dalton mRNA binding protein (as described by Shatkin and coworkers) will be examined. In addition to the indentification of those protein required for protein synthesis, experiments are in progress to define the biological function of these proteins, either in terms of the sequential utilization of the factors or in terms of defining the interactions a given factor may have with aminoacyl-tRNA, nucleotide triphosphates, mRNA, ribosomes or another factor. Presently, the major area of examination is the recognition and binding of mRNA to 40S subunits and the concomitant requirement for ATP hydrolysis.